Perimeter Perimeter of a shape is the total length of its sides. Perimeter of a rectangle length width length width = length + width + length + width P = l + w + l + w P = 2l + 2w P = 2(l + w)
Area Area measures the surface of something. 1 metre 1 square metre 1m 2 1 cm 1cm 2 1 mm 1mm 2
Area of a rectangular lawn 15 square metres The area is 5 metres long 3 metres wide Area of a rectangle= Length x Width = 15 m 2
Page 21 cm 30 cm = 30 x 21 Area of the page = 630 Field 65 m 32 m = 65 x 32 Area of field = 2080 cm 2 Area of rectangle = Length x Width m2m2 = 300 x 210 Area of the page = mm mm 210 mm
Units of Area 1 cm 1 square centimetre 1 cm 2 = 100 mm 2 1 cm 2 = 10 2 mm 2 1 cm = 10 mm
1 m 2 = 100 x 100 cm 2 1 m = 100 cm 1m 1 square metre 1 m 2 = cm 2 Units of Area 1 m 2 = 1000 x 1000 mm 2 1 m 2 = mm 2 1 m = 1000 mm 1 m 2 = cm 2 = mm cm 1000 mm
5.2 m 4.5 m 3 m3 m 3 m3 m 1.5 m 2.2 m Example L-shaped room Perimeter = A B = 19.4 m Area of A= 4.5 x 3 = 13.5 m 2 Area of B= 3 x 2.2 = 6.6 m 2 Total area = = 20.1 m 2
5.2 m 4.5 m 3 m3 m 3 m3 m 1.5 m 2.2 m Example L-shaped room A B Alternative Method Area of A= 3 x 1.5 = 4.5 m 2 Area of B= 5.2 x 3 = 15.6 m 2 Total area = = 20.1 m 2
5.2 m 4.5 m 3 m3 m 3 m3 m 1.5 m 2.2 m Example L-shaped room Yet another method! Area of large rectangle = 5.2 x 4.5 = 23.4 m 2 Area of small rectangle = 2.2 x 1.5 = 3.3 m 2 Total area = = 20.1 m 2